DEVICE_GET_CHILDREN(9)

💖 DEVICE_GET_CHILDREN 💖

okay bestie, welcome to section 9 of the Kernel Developer's Manual — yes, we're in the kernel dev manual, we're doing big brain stuff today, and honestly? it's giving main character energy. this is the page for device_get_children, and it's here to help you find out who's hanging out under a device. yes literally, its children. the whole little device family tree 🌳✨

✨ NAME ✨

device_get_children — get a list of devices connected to a device

like, the actual roster of who's attached. no cap. 👑

✨ SYNOPSIS ✨

#include <sys/param.h>
#include <sys/bus.h>

int
device_get_children(device_t dev, device_t **devlistp, int *devcountp);

first you gotta pull in those headers, <sys/param.h> and <sys/bus.h>, and then boom — that's the function signature, exactly like that. don't freestyle it 🫶

✨ DESCRIPTION ✨

so here's the vibe: you call device_get_children and it retrieves a list of all the device instances that are currently connected to dev, and it hands you back that list in *devlistp plus the count in *devcountp. like, here's your kids, and here's how many there are 💅

🎀 important, bestie: the memory allocated for that list? you gotta free it yourself with free(*devlistp, M_TEMP). the function is not gonna clean up after you. it's not your mom, it's a kernel function.

and one more thing — devlistp and devcountp are not changed when an error is returned. so if things go sideways, your pointers stay exactly where they were. no mystery edits. periodt.

✨ RETURN VALUES ✨

Zero comes back on success, obviously, slay. otherwise an appropriate error is returned — so like, check your return value, bestie, don't just assume it worked 😭

✨ SEE ALSO ✨

• devclass(9)
• device(9)

go read those too, iykyk 📚

✨ AUTHORS ✨

this manual page was written by Doug Rabson. iconic behavior, we love a documented kernel 💖

and that's the whole page, bestie! this lil' beauty lives in the Debian build of the Kernel Developer's Manual and it was last dated August 23, 2008 — yes, it's been serving accurate kernel facts since way before you were cool. go forth and enumerate those children 🌸🦋⭐